1. Field of the Invention
The invention concerns systems, components and methods for efficiently removing and disposing of the continuous, generally planar web of matrix waste formed during the high speed manufacture of adhesive backed, pressure sensitive label stock on a printing press.
2. Background Art
Pressure sensitive label stock has been and is manufactured on printing presses. Such presses are generally run at relatively high speeds, that is, up to 500-600 feet per minute. The label stock is made from a continuous web of two ply material. A layer of adhesive adheres the top ply of the web to the bottom ply. At one step during the manufacturing operation, the web is die cut, with the die cutter piercing only the top ply of the web. This die cutting step leaves only the labels, cut from the top ply, adhered to the lower ply. The remainder of the top ply is separated from the lower ply and constitutes a continuous, planar web of unwanted material, called a matrix or web of matrix waste, that has to be removed from the printing press. Desirably this continuous web of matrix waste should be disposed of with a minimum of cost and bother. Because of its adhesive layer or backing, this web of matrix waste is quite sticky and abrasive. It is bulky and generally difficult to handle.
In the past, one system used to remove and dispose of a web of matrix waste involved winding the matrix waste web on a core mounted on top of the printing press. The core is locked to a driven spindle and is controlled by a torque limiter. When the diameter of the roll of matrix waste reaches a maximum size, the full roll is removed and is replaced with a new core.
Another similar system has also been used. It utilizes two spindles. While the web of matrix waste is being wound on one spindle, the other is prepared with a new core. When the winding roll is "full", the web of matrix waste is automatically transferred to the new core. The "full" roll is then removed from the press and replaced with another, new core.
A third system has recently been used. In it, the web of matrix waste is crumpled into a generally tubular "rope" like shape and then this rope leads from the printing press to waste receptacles located near the press. This crumpling is achieved by leading the matrix web through a eductor. A stream of relatively high volume air is introduced about the periphery of the matrix rope, as it passes through the eductor, to carry the matrix rope through a flexible metal conduit that leads the matrix rope from the press to the waste receptacles. The interior of the eductor and the flexible metal conduit has a "non-stick", TEFLON brand coating to facilitate the passage of the matrix rope. This third system is marketed by Fox Trim Away of Charlotte, N.C. 28211.